China mostly builds nuclear reactors to retain the required industrial base to maintain a military nuclear program. Nuclear power is heavily subsidized in China, as it is everywhere in the world. It might be cheaper than in the US or Europe, but its not "cheap".

One of the bids for the third reactor was for KEPCO's APR-1400. Like the other bids, it was too expensive to make sense without subsidies.

China probably fits in the "politically undesirable" category these days.

There is no such thing as cheap nuclear reactor. Even cheaper Chernobyl type is expensive to build.

Considering the crazy amount of software and hardware backdoors built-in in buses, inverters, phones, routers, firewalls and mobile carrier devices it would be crazy to allow China to build the critical energy infrastructure.

How much per kW?

China and South Korea build everything more cheaply because they have a better developed industrial base.

Solar and wind is still vastly cheaper for them and still much cheaper when paired with storage.